# Non-standard compiler integration

**URL:** https://discourse.cmake.org/t/non-standard-compiler-integration/7315
**Category:** Usage
**Created:** [January 24, 2023, 9:18pm UTC](https://discourse.cmake.org/t/non-standard-compiler-integration/7315 "2023-01-24T21:18:38Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![steffen](https://discourse.cmake.org/user_avatar/discourse.cmake.org/steffen/32/3109_2.png) [@steffen](https://discourse.cmake.org/u/steffen)
#### Post date: [January 24, 2023, 9:18pm UTC](https://discourse.cmake.org/t/non-standard-compiler-integration/7315/1 "2023-01-24T21:18:38Z")

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I try to build a project with cmake, that uses a quite special compiler. It is about the xcc compiler from MicroSys for the os OS-9.  
The interface of the compiler differs from other compilers, like its objects files are instead of .o files .r files. All argument specifiers are different (eg. -L is -l) and so on.  
I was not able to find a documentation on how to add a custom compiler to cmake. Can anybody help, or knows where to find the documentation?

Best regards

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### Author: ![jtxa](https://discourse.cmake.org/user_avatar/discourse.cmake.org/jtxa/32/1535_2.png) [@jtxa](https://discourse.cmake.org/u/jtxa)
#### Post date: [January 26, 2023, 1:27am UTC](https://discourse.cmake.org/t/non-standard-compiler-integration/7315/2 "2023-01-26T01:27:50Z")

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Looking at their homepage I did not found `xcc`, but their OS-9 compiler seems to be Clang (based).  
So it may work pretty much already. Or is it an older self-made compiler?

Maybe you need to write a platform file, if the file extension is specific for OS-9 itself and not the compiler.

Writing compiler or platform files is not really documented. But there are enough other files to copy&paste from.